Topic: More power for my cb550

[Brauner cb550]

Im sorry if this was already covered on here, buy i have an 1975 cb550, i love the bike but id like some more power out of it.  Was wondering if cb650 jugs, pisons, and top end would fit on the bottom end?  My gf has a 1981 cb650 and her intake is shorter and would allow more space for carbs too. Thought maybe 650 jugs n top end with a 750 single cam?  Anyone done this before?

[Tews19]

Swap out a 1979-1982 650 engine. Direct bolt in.

[Brauner cb550]

I dont want to lose my kickstart as I use it all the time.  I was just curious if this would work.  I dont have alot of $ but i can find the 650 parts cheap. I know they put a 650 cam in the 550 but was hoping the jugs n top end would work as a cheap big bore kit without the machining. 

[Tews19]

Cal is correct on price too! The HP gain with a direct 650 swap is almost the same as a HI-PO 550 engine. 650 swap with wore harness and call it a day!

[Tews19]

I dont want to lose my kickstart as I use it all the time.  I was just curious if this would work.  I dont have alot of $ but i can find the 650 parts cheap. I know they put a 650 cam in the 550 but was hoping the jugs n top end would work as a cheap big bore kit without the machining.

I used to have the same.thought process as you in regard to the kick start but it's overrated. You can find a complete 650 engine, harness and if need be the controls for a few hundred tops. Depending on your location.

[jaguar]

Why would you use the kick starter all the time?

[philgresty]

Pick up a cheap 650 motor, spend on it what you would on your 550 and then burn off 750s all day.

[FunJimmy]

Don't forget to cost in a new exhaust should you decide to go the 650 engine route.

[Lostboy Steve]

....or just ride it.

I did very mild porting, exhaust and air filter, bumped up the jets, and aside from my cam tensioner issues, have had a reliable and rideable bike that I commute on. I'm regularly pushing time travel speed, and can keep up with my friends no problem on a fully loaded bike. Granted, it's not going to win in a race, but it's fine for what it is.


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[flatlander]

or looking at it from a different angle:
the stock 550 is not a very powerful bike and the 70s brakes don't help a modern, agressive riding style either. on real-life roads it can be pushed to keep up with other bikes (at a reasonable, not excessive speed) if the rider is able to make up for its deficits by making use of it's easy handling. that's my experience at least. before i started fiddling with it, i rode a 550 in stock shape for, i think, 2 years.

so another approach could be to improve on its benefits instead of trying to make up in an area where it's never going to win, anyway. that would mean work on suspension, chassis bearings, fork brace (!), maybe invest in some lighter/stiffer wheels... and add a bit more stopping power upfront.
and honestly, you'd need to do these things anyway if you want to benefit from a more powerful engine.

[flatlander]

p.s.
how on earth did i get a "master" title. now that's scary!
standards are really slipping on this forum...

[Stev-o]

p.s.
how on earth did i get a "master" title.

After fitting that 4-4 exhaust to your bike you were "Knighted" Master!


PS.  Kick starters are over rated, I have four bikes that I wish had elec starters!

PSS. Best way to get more power is to buy a 750...

[BomberMann650]

p.s.
how on earth did i get a "master" title. now that's scary!
standards are really slipping on this forum...

Oh the SoQ were gone the day the cow became an old timer.

[firebane]

Don't forget to cost in a new exhaust should you decide to go the 650 engine route.

I knew someone selling a "unknown" condition 650 engine for $150 but came with no exhaust.

It was the exhaust situation that made me NOT buy the 650 engine as I don't want to deal with that headache lol.

[BobbyR]

Get some Nirtros, instant power.

[lrutt]

Why don't you just enjoy the 550 for what it is. I have one and yea it's a dog compared to my Duc but it still puts a smile on my face.  If you want more power, get a 2nd bike that will scratch that itch. You can pick up a cheap supersport that will have twice the power or more for less than you'll spend trying to get another 20 hp out of that 550.

[SOHC4 Cafe Racer Fan]

I have a fairly stock 550, which I enjoy for what it is -- fun, rideable nostalgia.  I had a 750 with some performance mods (836 Wiseco, ported head, cam) and enjoyed the power but not the handling due to the weight of the overall bike.  That's why I decided to build a second 550 with a modified 650 engine (674 high compression kit, cam, ported head).  The goal is to have close to the 836's power-to-weight with much less weight overall. 

The stock 650 engine will give you almost as much performance as an overbored 550 engine, for a bunch less lucre.  If you want to burn money, it's better to start with the 650 and mod it. 

Unlike some others, I don't care so much about kick-starting my bikes. 

[Deltarider]

Why don't you just enjoy the 550 for what it is.

Right and realise that a 650 is operated 99,9% of the time at the same power that your 550 offers easily.

[TwoTired]

Im sorry if this was already covered on here, buy i have an 1975 cb550, i love the bike but id like some more power out of it.

Your desire may be assuaged by using a smaller front sprocket.
Makes it feel peppier, particularly around town, but trades off higher engine RPM on the freeway.

But, if you are going for engine work, the higher RPM will eventually get you their sooner. 

[SOHC4 Cafe Racer Fan]

Im sorry if this was already covered on here, buy i have an 1975 cb550, i love the bike but id like some more power out of it.

Your desire may be assuaged by using a smaller front sprocket.
Makes it feel peppier, particularly around town, but trades off higher engine RPM on the freeway.

But, if you are going for engine work, the higher RPM will eventually get you their sooner. 

TT,
I'm not sure where he's located but if anywhere like SoCal, that trade off will have your engine screaming to keep the bike at 75 on the highway.  It'll definitely pep it up.

Another way to wake up you bike is to swap to a 1/4 turn throttle.

If this is a nice looking stock survivor, I would not recommend the motor swap.  I would recommend it if you don't mind making it into a custom.

[TwoTired]

that trade off will have your engine screaming to keep the bike at 75 on the highway.

I had a 75 Cb550K that had one less tooth on the front sprocket.  Yep, higher RPM on the freeway, but it wasn't stupid high.  In the end, it wasn't for me, though.  But, then again, I'm happy with the power the 550 has.  I just use lower gears when I need to scoot, rather than rely totally on just throttle twist like the Harley guys do.

Another way to wake up you bike is to swap to a 1/4 turn throttle.

Because the CB550 does not have accelerator pump carbs, a quick turn throttle just makes the engine more sensitive to wheeze when you twist, as it can't take slide movement more than 1/2 of travel at low RPM.

If you keep the engine above 5K it will take any throttle change.   But, of course were back to engine screaming...

Cheers,

[SOHC4 Cafe Racer Fan]

Good stuff, Lloyd.

I try not to do too many freeway miles on my 550.  It's fun to take into canyons and to scoot around in town. 

I have the 1/4 turn throttle on it, but I don't get wheezing or bogging, but I also try to be smoother on the gas.  I just found I was having to twist the throttle quite a bit on the stock throttle.

[Gene]

PSS. Best way to get more power is to buy a 750...

^^^^^^

[CBGhia]

PSS. Best way to get more power is to buy a 750...

hmmmmmm         

You know I will see you in October.  Don't make it awkward.

[Stev-o]

PSS. Best way to get more power is to buy a 750...

hmmmmmm         

You know I will see you in October.  Don't make it awkward.

Ha!   I better get working on my 750...it has a big effin hole in the case!